A simple and versatile dual-state variable stiffness structure based on microwedge dry adhesives

The integration of softness and rigidity underpins the concept of variable stiffness, leveraging the distinct advantages of both properties. Inspired by this concept, this paper introduces a stiffness-switchable composite structure achieved through laminar jamming enabled by the inherent dry adhesion force of microwedge adhesives. This mechanism allows for a reversible transition between high flexibility and pronounced rigidity, achieving a remarkable stiffness ratio of 75, with easier implementation and enhanced functionality. Comprehensive modeling and experimentation are conducted to reveal intricate aspects of the structure’s mechanical properties, such as interlayer behavior and failure processes. This paper also outlines two potential applications for this multifunctional structure: a robotic gripper with dual modes of rigid pinch and compliant adhesion, and an integrated multifunctional sensing setup. The proposed structure might broaden the scope of dry adhesives and laminar jamming structures, suggesting new possibilities for future research and development.